(1) Field of the Invention
It is customary for ISO (International Standards Organisation) containers to have standard corner fittings by which the containers are latched to the container-carrying platforms of transport vehicles by means of twist-locks which enter the corner fittings from beneath. However, such twist-locks depend beneath the container-carrying platform of the vehicle and accordingly require a suitable clearance beneath the platform.
(2) Description of the Prior Art
Proposals have been made for twist-lock alternatives to be used at the front of container-carrying vehicle platforms, such alternatives being mounted in, and operating in, a generally horizontal plane such as to obviate the need for vertical clearance beneath the platform. To obviate excessive first cost, such twist-lock alternatives are relatively simple mechanical arrangements which are manually operated. One such arrangement includes a horizontally retractable locking pin coupled to a manual operating lever. For reasons of safety, the locking pin has to be latched to its extended container-locking position. This prior art arrangement has a vertically swingable latch which engages the operating lever to hold the lever, and hence hold the locking pin in its extended position. However, to unlatch and re-latch the operating lever, the latch requires manual operations distinct from the manual operation of the pin-operating lever, and the prior-art arrangement therefore requires two distinct and co-ordinated manual operations. Moreover, the swingable latch of this prior art arrangement depends on the affect of gravity on the latch to hold the operating lever latched during container-transporting vehicle movements. Thus, not only does the latch require manual resetting into its lever-latching position, jolting of the vehicle during transport can dislodge the latch, so freeing the locking pin and potentially allowing the dangerous situation of the container becoming unlocked from the transport vehicle.